If you can find one of these used (they have been out of business for 3 years) it works very well. It is what I am using for an auto water change. https://reefs.com/product-review-genesis-reef-systems-renew-part-1/
my new unit also has a B failure after changing reagents. It looks like no reagent is being drawn. Seems like my unit is functioning like normal besides testing the B. If I don't care that the B is not working does it matter?
Not sure why I was successful, but I did start with dry rock for my current tank. I added a lot of SPS with in the first couple of months. My biggest struggle was definitely microbiome related, primarily regarding stability of nutrients and diatom/cyano blooms. It was a constant battle for...